The present invention relates to restructured coal and, more particularly, to a tube-like coal article. Moreover, the invention relates to a method of burning coal without consuming the free carbon thereof.
Chunks of coal may be satisfactorily burned in controlled, relatively closed environments, e.g. in a furnace, boiler, stove, etc. Usually there is sufficient air, for example provided by a forced or other artificial draft, to assure substantially complete combustion of the coal; and as long as there is sufficient combustion, temperature and air, additional coal introduced to such controlled environment also will burn. To facilitate such burning in some cases the coal is pulverized to relatively small particulate form before or as it is delivered to the combustion area. The residue of such substantially complete combustion is ash, which usually is not valuable for further energy-related purposes and often is difficult and messy to dispose.
In the past relatively controlled and complete burning of coal in relatively open environments, e.g. in a home fireplace, a campfire, or the like, has met with unsatisfactory results. Moreover, the sparks and fly ash, which are produced when coal is ordinarily burned, are further disadvantages that would be encountered when trying to burn coal in such open environments.
When coal is mined to obtain the usual chunk-like pieces of coal, coal fines, which are relatively particle-like or powder-like, also usually are produced. However, such coal fines customarily have been considered a nuisance due to the difficulty of storing and transporting the same, for example, and frequently such fines have been discarded.
In the past, efforts were made to burn solid log-like coal articles. These efforts, however, had unsatisfactory results unless the coal log were burned in the aforementioned controlled environments. To burn such a solid coal log in an open environment, such as a fireplace or a campfire, has been found very difficult and sometimes impossible.
Coke, which is mostly pure carbon, is a useful product derived from coal. One well known important use of coke is in the making of steel. To make coke itself, coal is delivered into a coking or by-product oven or a beehive where the coal is heated in a relatively low oxygen or oxygen-free environment without any substantial combustion of the coal. In the oven or beehive gas, referred to as coal gas, producer gas, water gas, and the like, which includes substantial amounts of combustible methane, and other by-products are emitted by the coal, leaving at the end of the process, as is well known, coke of relatively pure carbon composition. In some coking processes the gas may be recovered and burned as a supplemental fuel to provide heat for continuing the coking process.